Researchers have found that men who had slept with more than 20 women during their lifetime had a 28 percent lower risk of developing prostate cancer.
According to the study men who were virgins were almost twice as likely to be diagnosed with prostate cancer as those who were sexually experienced, the Independent reported.
Lead researcher Professor Marie-Elise Parent, from the University of Montreal has said that having many female sexual partners resulted in a higher frequency of ejaculations, whose protective effect against prostate cancer has been previously observed in cohort studies.
According to one theory, large numbers of ejaculations could reduce the concentration of cancer-causing substances in prostatic fluid, a constituent of semen and may also lead to fewer crystal-like structures in the prostate that have been associated with prostate cancer.
The findings were from the Prostate Cancer and Environment Study in which 3,208 men answered questions about their lifestyle and sex lives.
A total of 12 per cent of the group had reported having had at least one sexually transmitted infection (STI) in their lifetime.